In order to properly handle sprite priority, you need to do things a bit differently.

Instead of drawing sprites in the order 63->0 and drawing lower numbered sprites on top of higher numbered ones, draw them 0->63 but only allow each pixel on the screen to be occupied by *one* sprite.

The important bit here is that sprites drawn behind the background are still treated as being drawn, so a higher numbered sprite will NOT be rendered in that particular location.

Note that all of this is per-pixel, and transparent sprite pixels do not count.

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Quietust
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